1. Field of the Invention:
The present invention relates to a transformer apparatus having rectifiers for use in a resistance welding machine, etc.
2. Description of the Prior Art:
Conventionally, there are known two apparatuses as shown in FIGS. 5 and 6 as an apparatus of the type described above. One is adapted, as shown in FIG. 5, to have rectifiers 23, 24 respectively provided on the front of secondary electrode plates 21, 22 each connected to both ends of a secondary coil 20 as well as a common output terminal plate provided on the front of the rectifiers (refer for example to Japanese Laid-Open Patent Publication No. 61-33622). The other is adapted, as shown in FIG. 6, to have rectifiers 33, 34 respectively provided interiorly of secondary electrode plates 31, 32 extending in parallel from both ends of a secondary coil 30 in the forward direction thereof as well as a common output terminal plate 35 provided interiorly of the rectifiers (refer for example to Japanese Laid-Open Patent Publication No. 61-33620).
In such a prior apparatus as shown in FIG. 5, a protrusion frontally projecting from the transformer can be reduced, but in welding in need of a large current the rectifier must have a greater diameter to result in disadvantageously the size L of the transformer apparatus made large when the secondary electrode plates 21 and 22 and the rectifiers 23 and 24 are disposed vertically and horizontally respectively, and thus the rectifiers are obliged to be protruded widthwise from the transformer and to permit the whole apparatus to be large-sized.
On the other hand, also in the prior apparatus of the type shown in FIG. 6, protrusion projecting widthwith from the transformer can be eliminated, but the respective electrodes are adapted to extend frontally from the transformer, and thus the apparatus is made longer as a whole.